Re: [PATCH v1 03/11] perf: Allow for multiple ring buffers per event

Peter Zijlstra
2014-05-08T12:41:31Z

[-- Attachment #1: Type: text/plain, Size: 660 bytes --]

On Thu, May 08, 2014 at 03:34:17PM +0300, Alexander Shishkin wrote:
> Peter Zijlstra <peterz@infradead.org> writes:
>
> > So the aux_head/tail values should also be in the file space and not
> > start at 0 again, similar for the offsets in the AUX record.
>
> Thinking some more about it: if we keep aux_{offset,size} in userpg,
> then it would make sense to have aux_{head,tail} run from 0 to infinity
> similar to data_{head,tail}, especially considering that neither data_*
> nor aux_* pointers are file offsets anyway.

Yeah, this might make it easier. So then the rule is *_offset +
*_{head,tail} is the actual file offset into the buffer.

[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]